Touchscreen interfaces are used in many applications, from cellular telephones to point of sale kiosks. Touchscreen devices enable a user to interact with a display device by pointing or touching the surface of the display.
Several different technologies may be used in touchscreen devices. Two commonly used technologies are resistive touchscreens and capacitive touchscreens. A resistive touchscreen is one in which the resistance change between two translucent sheets is measured when a user presses a point on a display. A capacitive touchscreen measures the capacitive change between a user's finger or stylus and the surface of a display to detect the presence and position of the touch. In both cases, the touchscreen sensor is placed over the surface of the display.
Some touchscreen input devices may be calibrated on first use or periodically over the lifetime of a device. Such calibration can be tedious and sometimes confusing to a user.